Hello,
i just downloaded the mdadm 2.2 version. It seems that there are some
new options which are not explained in details. of special interest are
2 options.
-GROW
The new grow mode is very very helpfull for us. It would allow us to do
resize operations with md devices at last - without the need for LVM.
The manpage states that the GROW mode requires kernel support to work.
There is no note that states, which kernel supports the options. Also
with various distributions with patched kernels its not possible to say
version X.Y.Z. of the kernel contains the required patches.
Is there a way to find out via mdadm, if the current kernel supports the
GROW mode, prior to performing the GROW ?
-bitmap
As far as I understand this bitmap options, in incorperates write intend
logging.
Is this based on paper by James Bottomley ? Also is there a way to find
out via mdadm if the running kernel supports intend logging via mdadm ?
-There is also an option --write-mostly since 2.0.
I guess this especially usefull for MD devices with large storage arrays
as backend. They have clever caches and read ahead paramaters, that can
be non-effective if we change the disk for each read. Does this option
require a kernel modification too ?
One last question. Besindes the source code and manpage is there oterh
documentation available on how the md works internally ? (update of
superblock, handling of device renaming inside the superblock etc.)
Thanks,
Robert Heinzmann
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
